Was having a look at the slicks off the Esky after Bathurst, and found what looks like some unusual wear patterns on the rears. Was wondering if any tyre gurus out there can explain what it means.

Basically if you look at the picture below, the LHS is the inside and the RHS is the outside. On the inside at the edge there is a very shallow concave section before the main area of the tread. Also the rubber looks like it's been pushed from the inside towards the outside, as the outer edge has the rubber buildup (unlike the fronts where the rubber buildup is on the inside).

Suspension is English housing with 5 link and slipper'd leaf springs. Tyres are Hoosier crossply slicks and pressure was 20lb cold which came up to 24lb hot.

I hadn't seen this previously after QR or MP but then the tyres hadn't done 280km of racing. Anyone have any ideas why the rears would wear like this

maxrs -nitrogen does increase & decrease pressure with temp variants
but not as much as the typical compressed air , as compressed air is
high in h/20
a relativly inert gas like nitrogen is much more
predictable for press increase vs temp
typicaly we will settyre pressures on the
sports sedan using nitrogen , about 3 to 5 psi lower
than the desired pressure
to start with
an example is , 24 psi cold = about 28 psi hot
nev
its just my opinion but your rear tyres look
under inflated !! stupid cross plys dont like that !!!
pressure is precious

gen mk 1rs2000 wrote:maxrs -nitrogen does increase & decrease pressure with temp variants but not as much as the typical compressed air , as compressed air is high in h/20 a relativly inert gas like nitrogen is much more predictable for press increase vs temp typicaly we will settyre pressures on the sports sedan using nitrogen , about 3 to 5 psi lower than the desired pressure to start with an example is , 24 psi cold = about 28 psi hot nev its just my opinion but your rear tyres look under inflated !! stupid cross plys dont like that !!!pressure is precious

nev , when i got my car the diff housing had been put in a big hyd press
& had about 1.5 deg neg camber , but used to chew up rear wheel bearings
it was one of the slightly cheating tricks
they used in the old group C days
but i prefer the rally method
rather than a hyd press
its more spectacular

All nice thoughts but as a log booked Historic car with a C of D, it can only have what it had at it's competition event which is Bathurst 79. So swapping diffs is out as is bending the one that's in there. It didn't have it then so it can't have it now.

I'll change the tyre pressures and see how that goes. Thanks all for the input.

All diffs 'from the factory' would have been made to a +/- tolerance, bending it would just be taking it to one of those tolerances, the negative one of course. Even 1/2 deg might make some sort of difference.